The filter I used a long time ago that worked at the time was a hostname one using (.?localhost.?)

Filter Name: Exclude localhost
Filter Type: Custom filter > Hostname
Filter Pattern: (.?localhost.?)
Case Sensitive: No

Now I block via code so I'm not sure if this still works - feel free to try.  Also, I'm not sure why the filter uses both * and ? since the star should be inclusive of ? wildcard but I can no longer find the source.

Good luck